This invention relates to an XY recorder, in which recording paper is moved in the X direction in accordance with one variable, and a stylus is moved across the paper in the orthogonal Y direction in accordance with another variable.
Many types of such XY recorders use paper perforated along its edge (or edges). The paper is moved with a sprocket wheel (or wheels) engaged to the perforations. For such perforated paper, a paper alignment is satisfactory, because the perforations on a paper edge (or edges) are aligned to paper. But perforated paper is expensive.
Some types of such XY recorders use ordinary paper without perforations. But heretofore known XY recorders using non-perforated paper either have problems on paper alignment or have such an elaborate mechanism as disclosed by a U.S. Pat. No. 4,216,482 invented by Martin K. Mason.